Conjugate Vaccine

A conjugate vaccine is a type of subunit vaccine that combines a weak antigen with a strong antigen used as a carrier, so that the immune system produces a stronger response to the weak antigen than it otherwise would. Vaccines work by provoking an immune response to an antigen, a part of a bacterium or virus that the immune system can recognize, usually through an attenuated or dead version of the pathogen, but some pathogens carry antigens too weak on their own to elicit lasting protection. In a conjugate vaccine, such a weak antigen, most commonly a polysaccharide, is covalently attached to a strong protein antigen carrier, producing a stronger immunological response; peptide-protein and protein-protein conjugates have also been developed.